The present disclosure relates generally to image processing and, more specifically, to techniques for inverse dithering images using an energy diffusion approach.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
In recent years, electronic display devices have become increasingly popular due, at least in part, to such devices becoming more and more affordable for the average consumer. In addition to a number of electronic display devices currently available for desktop monitors and notebook computers, it is not uncommon for digital display devices to be integrated as part of another electronic device, such as a cellular phone, a tablet computing device, or a media player. Further, it is not uncommon for digital devices to be connected to a second electronic display device, such as a television or projector, suitable for providing a larger display area.
Certain devices, such as portable devices, may use lower bit displays (e.g., 6-bit displays) to present visual information, and dithering techniques may be used to create the appearance of higher-bit depth (e.g., 8-bit) to the human eye. Additionally, electronic displays are typically configured to output a set number of colors within a color range. In certain cases, a graphical image to be displayed may have a number of colors greater than the number of colors that are capable of being shown by the electronic display. For example, a graphical image may be encoded with a 24-bit color depth (e.g., 8 bits for each of red, green, and blue components of the image), while an electronic display may be configured to provide output images at an 18-bit color depth (e.g., 6 bits for each of red, green, and blue components of the image).
Rather than simply discarding least-significant bits, dithering techniques may be used to output a graphical image that appears to be a closer approximation of the original color image. That is, when the dithered image is displayed on the electronic device (e.g., cell phone, laptop, workstation), the dithered image looks substantially the same to the human eye as the original source image. However, although the dithered image is visually pleasing to the human eye on certain displays, other displays may apply image processing techniques, such as edge enhancement techniques which may find “false” edges in the dithered image due to quantization steps performed during dithering. These “false” edges may be amplified during the edge enhancement, resulting in visual artifacts such as halos and/or rings.